speedometer changes with upsize tires
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From: Chesterfield Virginia
speedometer changes with upsize tires
I just put an 18/19 wheel and tire package on my 02Z. Looking at the old and the new tires it's a little taller. A friend told me that the computer automatically makes changes to adjust speedometer calibrations. I think that the changes have to be loaded with a programmer or a tune . Can anybody shed some light on this or is it not enough of a difference to bother with it.?
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St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
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From: Calgary, AB. There's a reason why white was the only color offered on every year Corvette. Proud Canadian German Jamaican!
St. Jude Donor '09, '12-'13-'14-'15-'16-'17
As long as the ratios are the same between the old and new you'll be fine but it's not only the speedo you have to worry about it's the traction control. I have winters on the fronts and backs and the front's are slightly larger than the factories so when I floor it the traction control kicks in but if I turn the TC off then it's fine, no big deal, but just something to be aware of.
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As long as the ratios are the same between the old and new you'll be fine but it's not only the speedo you have to worry about it's the traction control. I have winters on the fronts and backs and the front's are slightly larger than the factories so when I floor it the traction control kicks in but if I turn the TC off then it's fine, no big deal, but just something to be aware of.
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St. Jude Donor '05-'06
Figure out the circumference of the old and new tires, if they are very close to the same then there is no issue.
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From: Calgary, AB. There's a reason why white was the only color offered on every year Corvette. Proud Canadian German Jamaican!
St. Jude Donor '09, '12-'13-'14-'15-'16-'17
So for argument sake all the tires are the same size and you go from a 275/40/18 to a 285/35/19 the speedo will be out?
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275/40/18
tire diameter -26.661
Tire Circumference - 83.758
285/35/19
tire diameter -26.854
Tire Circumference - 84.364
The circumference is out by a half inch so the speedo will not be effect that much not enough to be worried about.
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From: Mt. Airy MD
You could just borrow someone's GPS if you do not have one and go for a ride. The GPS will tell you how fast you are going. I found mine to be pretty accurate across three cars so I have no reason to believe it can't be used to tell you if your speedo is now off or if its still tracking correctly. From there decide what you want to do.
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Here is the calculation for the tire size you put in your post
275/40/18
tire diameter -26.661
Tire Circumference - 83.758
285/35/19
tire diameter -26.854
Tire Circumference - 84.364
The circumference is out by a half inch so the speedo will not be effect that much not enough to be worried about.
275/40/18
tire diameter -26.661
Tire Circumference - 83.758
285/35/19
tire diameter -26.854
Tire Circumference - 84.364
The circumference is out by a half inch so the speedo will not be effect that much not enough to be worried about.
with the tires being so close in height, you will only be off by about 1/2 mph at a speed of 80 mph. Nothing I would worry about.
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From: Calgary, AB. There's a reason why white was the only color offered on every year Corvette. Proud Canadian German Jamaican!
St. Jude Donor '09, '12-'13-'14-'15-'16-'17
that's what I use.
